CVE-2024-56527 is a high-severity (CVSS 7.5) Cross-site Scripting (XSS) vulnerability in tecnickcom/tcpdf. A fix is available for tecnickcom/tcpdf — see the affected versions and patch details below.
TCPDF missing character escape on error messages
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-56527.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
tecnickcom/tcpdfReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
An issue was discovered in TCPDF before 6.8.0. The Error function lacks an htmlspecialchars call for the error message.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | tecnickcom/tcpdf | all versions | 6.8.0composer require tecnickcom/tcpdf:^6.8.0 |
Affected Products
tcpdftcpdf_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tecnickcom/tcpdf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tecnickcom/tcpdf to 6.8.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-56527 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2024-56527 in your dependencies?
Find it across Packagist, including transitive dependencies.